For example, the dispenser or at least the reservoir can be made up from one or two flexible sheets forming the actuating wall. By pushing in the actuating wall against the spring means, it is possible to reduce the internal volume of the reservoir, and fluid is thus delivered through the dispensing orifice. That is a conventional design for a dispenser in the fields of perfumes, of cosmetics, or indeed of pharmaceuticals. In certain fields, it is advantageous for fluid to be dispensed in the form of a spray.
When the actuating wall is deformable, the spring means act on the wall to deform it towards a maximum deformed state in which it defines a maximum volume state for the reservoir. Deforming the deformable wall by using spring means is not always attractive and can adversely affect the appearance of the dispenser. In addition, the spring means increase the total thickness of the dispenser, and that can be a major drawback in certain uses.
Document FR-2 791 645 discloses a dispenser of that type in which the dispensing orifice is closed off by a removable closure member prior to use. The inside of the reservoir therefore does not communicate with the outside and, in that document, the spring that acts on a deformable wall is compressed to a maximally compressed state, so that the thickness of the dispenser can maintained at a minimum. That is an essential requirement when such a dispenser is to be inserted in magazines in the form of a fluid sample. Even when the dispensing orifice is closed off, the spring naturally acts against the deformable wall, thereby unattractively deforming the deformable wall which then often presents uneven relief.
Prior art dispensers are also known in which the actuating wall is not deformable, but rather merely displaceable.